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Scaleout Inhibitor


Product code — SI-28

A superior conditioning performance thanks to a unique, food-grade catalytic core treatment method. Protecting water outlets and household appliances such as boilers, showers, hot water tanks, washing machines, dishwashers and kettles.

  • Leading 10 year parts warranty for complete peace of mind.
  • World leading technology since 1973 – utilising a unique catalytic core within a quality stainless steel body.
  • Water remains treated for up to 3 months.
  • Prevents new and removes existing scale from your system.
  • Self cleaning action to keep the media core working at optimum efficiency.
  • No maintenance – fit and forget.
  • No earth bonding is required.
  • Designed and made in the UK with full WRAS Approval.
  • Installation is straightforward and can be connected to any type of pipe – copper, pvc, galvanized, etc.
  • Can be installed vertically or horizontally.
  • Reduces energy bills and prolongs equipment life.

3 stages for the ultimate conditioned water:

  1. A unique aerator screen which optimises turbulation and helps separate the bicarbonate (which causes scale).
  2. Pioneering spiral alloy core combined with innovative surface chemistry composition to create a powerful catalytic reaction and long-lasting treatment.
  3. The result is the conversion of scale causing ions into non-scale forming crystals which flow freely through the system without leaving hard scale deposits.

210 x 49.5 LxØ (mm)

Number of people: 6+ (28mm or 35mm pipework)

Optimum Flow Range (lpm): 34 – 62

Max Pressure (bar): 16*

Op. Temp (°C): 1 – 99

Connection: 1” fbsp

* We recommend a PLV for all water pressures over 5 bar.

Additional Information

Which water softener is best for you?

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Enter your postcode below to check your water hardness. It is important to know if you have hard or soft water.


Re-Introducing — 
the Midi HE Softener

The Midi HE is the UK’s best-selling softener in the merchant channel and the number 1 choice for UK installers. The WRAS-approved Midi HE is high efficiency and provides the ultimate protection against limescale.

Monarch Champions — 
People you can trust

We’re so confident our products will meet your needs that we’ve assembled a group of existing customers – our ‘champions’. Our advocates will directly answer any questions you may have, from installation to living with a Monarch Water product.

Ecologi —
Climate action at your fingertips

Simple and impactful ways to collectively reverse climate change.

The Eczema

Monarch is the perfect partner for The Eczema Academy, offering a multitude of sustainable, WRAS-approved water treatment products that can help alleviate skin conditions, such as, eczema. Carolyn Akinyemi, founder of the academy said: “We are extremely happy to be working alongside Monarch – a reputable and innovative company that offers a number of softening and filtration solutions, which are key components in the effective protocols for the relief of Eczema”.

Together, Monarch and The Eczema Academy aim to educate people on how they can help relieve and control their Eczema. Ian Flack, Monarch’s head of sales said: “We are proud to be supporting Carolyn and The Eczema Academy. We are looking forward to working closely with her going forward to help convey the benefits that soft water can bring to those affected by eczema”.

If you would like to find out more about The Eczema Academy, visit or email

Keep up-to-date with all the latest from The Eczema Academy by subscribing to their YouTube channel here.